We take a closer look at the processes responsible for making upper ocean fronts highly productive. With high resolution modeling and sampling, we are uncovering a range of dynamic instabilities and processes at the kilometer length scale in frontal zones. Regions are developed, where the local Rossby number exceeds 1, the flow is highly ageostrophic, and large vertical velocities of order (100 m/day) are developed. The intense vertical motions restratify the mixed layer, transport nutrients for phytoplankton, and affect the spatial heterogeneity of biogeochemical properties. In this talk, we present our understanding of submesoscale processes based on numerical model simulations and explore the implications of these processes on biological productivity. We consider the effects of vertical motion, as well as lateral stirring, on phytoplankton distributions.